The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
As this is known per se, with an aircraft engine nacelle, it is possible to channel the outside air towards this engine and to ensure ejection of this air at a high velocity so as to provide the required thrust.
In dual flow turbine engines, the air flow blown by the fan is divided, downstream from the latter, into a primary flow (also said to be a <<hot>> flow) which enters the core of the turbine engine so as to undergo several compressions and one expansion therein, and into a secondary flow (also said to be a <<cold>> flow), which circulates inside a substantially annular vein, defined by fairing of the engine (fixed internal structure, also called <<IFS>>) on the one hand, and by the thickness of the nacelle on the other hand.
The cold air flow, which flows out downstream from the nacelle through an outlet jet pipe nozzle defined by the downstream edge of this nacelle, provides the main portion of the thrust.
For reasons of aerodynamic optimization, and thereby optimization of the fuel consumption, it is quite advantageous to be able to adjust the cross-section of the outlet of the cold air flow downstream from the nacelle: indeed it is useful to be able to increase this cross-section during take-off and landing phases, and to reduce it during cruising phases: this is often referred to as an adaptive nozzle, or still further as <<VFN>> (Variable Fan Nozzle).
Moreover, as this is known per se, the nacelle very frequently incorporates thrust reversal means giving the possibility of directing towards the upstream side of the nacelle a portion of the secondary air flow during landing, which actively contributes to braking the aircraft.
These thrust reversal means are often of the type with deflection grids, i.e. they include a series of grids positioned downstream from the fan case, at the periphery of the cold flow vein, these grids may be exposed on command by a thrust reverser cowling slideably mounted on the structure of the nacelle.
The outlet jet pipe nozzle of the secondary air flow is located in the downstream extension of the thrust reverser cowling, and it is important to be able to actuate both of these portions of the nacelle independently: the intention is in particular to be able to increase the cross-section of the nozzle without actuating the thrust reversal means, in particular during take off.
Various solutions exist in the state of the art for actuating these members independently of each other.
A known solution consists of providing independent cylinder actuators for both of these members.
Another known solution consists of using dual rod cylinders, one rod actuating the thrust reverser cowling and the other rod actuating the outlet jet pipe nozzle.
Still another solution consists of using actuators which only actuate the outlet jet pipe nozzle, and of providing controlled means for locking the reverser cowling to the nozzle, which are closed when the nozzle is at the downstream end-of-travel in order to be then able to drive the thrust reverser cowling, and which are opened once that the thrust reverser cowling has again found its <<direct jet>> position, in order to be able to bring back the outlet jet pipe nozzle to its upstream position.
All these prior solutions have notably the drawback of having a high weight, because of the specific actuators and/or of the locking means used for allowing independent actuation of the reversal cowling of a reverser and of the ejection nozzle.